For the Koala’s, mating generally occurs between December and March. They don’t see to have the natural instinct for reproducing though at the same level as many other animals. Females and males are ready to mate between 2 and 3 years of age.
Males and females attract each other for mating through deep bellowing calls and scents. The males usually will initiate them and wait for females to respond. They may grow a great deal during this process as a warning to other males to stay out of that area. They can become highly aggressive during the time of the year when they are looking for females to mate with.
The mating ritual isn’t long and the males are often seen biting the females on the back of the neck. The making process lasts two minutes or less and then they go their own ways. Mating can use up energy and the Koala doesn’t have much of it to spare. If the Koalas feel stressed or they don’t have enough food then they may avoid mating.
There are reports of mating occurring in many areas of Australia but no offspring being produced. Through careful research it is believed that a microorganism known as Chlamydia is found there. It can be transferred from one Koala to another through sexual contact. It can also make them sterile which means they aren’t able to reproduce even though they can take part in mating.
This can be a serious problem because it can result in areas where the Koalas live having a very low number of offspring in the future to replenish the population. Efforts are being made to identify all of the various microorganisms in their environment that can contribute to this problem. Hopefully they can be eliminated to help the Koalas with reproducing successfully.
The females don’t produce young all the time. In fact, they average a new baby about every 2 or 3 years. As a result the rate of growth among these animals is extremely slow. Even with zoos and various organizations out there doing all they can they are at a high risk of extinction.
Once a female is carrying young, she will give birth only about 35 days later. It is almost always one baby that is born. However, there are some confirmed cases of twins arriving.